Nowadays, more and more terminal devices' screens support touch type human-machine interfaces. Among the touch type interfaces, capacitive touch screens have been widely used. The capacitive touch screens currently widely used in mobile terminal devices such as mobile phones, tablet PCs or notebook computers provide users with fresh new operation experiences. However, the capacitive screens have some defects. One of the defects is that the capacitive touch screen is unable to detect a force of a touch and therefore the touch terminal device is unable to reliably distinguish between accidental and intended touch operations. This problem is especially apparent for some key-press operations. For example, when performing some key confirmation operations, a hesitant or accidental touch by a finger may also be detected and recognized as an intended touch, thus leading to an undesirable result. If this touch operation relates to transaction and payment, it may cause bigger safety potential and more serious consequences.